Emerging medical technologies are substantially improving our health care options, but often at considerable added cost. Cost-effectiveness and affordability are described as the fourth and fifth hurdles for new medical technologies, following the traditional three hurdles for licensing requirements: safety, efficacy, and quality. The Human Genome Project offers ample opportunity to improve human health through innovative genome-based technologies that have only recently become available. A number of genomic prognostic and predictive tests have been developed to assist physicians in providing better treatment for patients with early-stage breast cancer (ESBC). Clinical use of these emerging genomic tests will depend not only on the accuracy of the tests but also on their economic impacts to the society. The purpose of this study is to use methods of economic evaluation to examine the relationship between the performance of pharmacogenomic prognostic and predictive tests and their costs over a plausible range of test performance and costs for women with ESBC in the context of costeffectiveness and affordability. The specific aims are the following: [unreadable] 1. To compare the cost-effectiveness of using pharmacogenomic prognostic tests versus current practices in the treatment of ESBC [unreadable] 2. To assess the cost-effectiveness of using pharmacogenomic predictive tests versus current practices in the treatment of ESBC [unreadable] 3. To evaluate the cost-effectiveness of using a combination of pharmacogenomic prognostic and predictive tests versus current practices in the treatment of ESBC [unreadable] 4. To estimate the budgetary impact of the emerging pharmacogenomic prognostic and/or predictive tests [unreadable] [unreadable] [unreadable]